Docker NodeJS 应用程序无法连接到 postgres 数据库

Question

I am farely new to docker and docker-compose. I tried to spin up a few services using docker which contain of a nodejs (Nest.js) api, a postgres db and pgadmin. Without the API (nodejs) app beeing dockerized I could connect to the docker database containers, but now that I also have dockerized the node app, it is not connecting anymore and I am clueless why. Is there anything wrong with the way I have set it up?

Here is my docker-compose file

 version: "3" services: nftapi: env_file: -.env build: context: . ports: - '5000:5000' depends_on: - postgres volumes: -.:/app - /app/node_modules networks: - postgres postgres: container_name: postgres image: postgres:latest ports: - "5432:5432" volumes: - /data/postgres:/data/postgres env_file: - docker.env networks: - postgres pgadmin: links: - postgres:postgres container_name: pgadmin image: dpage/pgadmin4 ports: - "8080:80" volumes: - /data/pgadmin:/root/.pgadmin env_file: - docker.env networks: - postgres networks: postgres: driver: bridge

This is the nodejs app Dockerfile which builds successfully and in the logs I see the app is trying to connect to the databse but it cant (no specific error) just that it doesnt find the db.

 # Image source FROM node:14-alpine # Docker working directory WORKDIR /app # Copying file into APP directory of docker COPY./package.json /app/ RUN apk update && \ apk add git # Then install the NPM module RUN yarn install # Copy current directory to APP folder COPY. /app/ EXPOSE 5000 CMD ["npm", "run", "start:dev"]

I have 2 env files in my projecs root directory.

1. .env
2. docker.env

As mentioned above, when I remove the "nftapi" service from docker and run the nodejs up with a simple npm start it is connecting to the postgres container.

 TypeOrmModule.forRoot({ type: 'postgres', host: process.env.POSTGRES_HOST, port: Number(process.env.POSTGRES_PORT), username: process.env.POSTGRES_USER, password: process.env.POSTGRES_PASSWORD, database: process.env.POSTGRES_DB, synchronize:true, entities: ['dist/**/*.entity{.ts,.js}'], }),

The host from the.env file that is used in the typeorm module is localhost

Answer 1

When using networks with docker-compose you should use the name of the service as you hostname.

so in your case the hostname should be postgres and not localhost

You can read more about at here: https://docs.docker.com/compose/networking/